Applicator for use in chromatographic analysis



March 3, 1964 K. J. MUTTER APPLICATOR FOR USE IN CHROMATOGRAPHIC ANALYSIS 2 Sheets-Sheei 1 Filed Feb. 12, 1962 H, m II/III III II III/9r] INVENTOR. Karl Josef Muffer HIS ATTORNEY K. J. MUTTER March 3, 1964 APPLICATOR FOR USE IN CHROMATOGRAPHIC ANALYSIS 2 Shee ts-Sheet 2 Filed Feb. 12, 1962 INVENTOR.

Kar/ Josef Mufler HIS ATTORNEY United States Patent 3,122,781 APPLECATOR FOR USE IN CERGMATGGRAPC ANALYSE3 Karl Josef Mutter, Birsfelden, Basel-Land, Switzerland,

assignor to Camag, Chemie-Erzeugnisse und Adsorptionsteehnik AG, a corporation of witzerland Filed Feb. 12, 1962, Ser. No. 172,642 Ciaims priority, application Germany Feb. 20, 1961 6 Claims. (Cl. 18-1) The present invention relates to an applicator for providing uniform layers of adsorbent-containing material for use in chromatography or more particularly in chromatographic analysis.

In so-called thin-layer chromatography (also referred to as chromatostn'p, chromatoplate, or microadsorption chromatography which is a recent development in laboratory technique, the practice requires the provision of thin layers of adsorbents on suitable supports, such as glass or other sheets. It is of importance in this technique that layers be of uniform thickness and that means for providing them be simple and effective.

The invention, described more specifically hereinbelow, comprises a reservoir means, and means by which supporting sheets may be successively passed through the reservoir to apply adsorbent-containing material to one side of a supporting sheet and to provide a layer thereon of uniform thickness. Adjusting means are included whereby the thickness of a layer may be varied. Means are also included whereby an adsorbent layer may be provided on sheets of different widths with a high degree of exactness.

Reference is made to the accompanying drawing in which FIG. 1 is an applicator seen in isometric perspective; FIG. 2 is a longitudinal sectional view of the applicator in elevation; FIG. 3 is a view, partially in section, taken on line IIIIII of FIG. 2; FIG. 4 is a view, partially in section, taken on line IVIV of FIG. 2; FIG. 5 is a View similar to FIG. 3 but illustrating adjustment of the applicator for treating sheets of a different width; FIG. 6 is a detailed view of adjusting means employed in changing the thickness of coatings; FIG. 7 is a plan view of the applicator; FIG. 8 is a detailed view of a modification of means shown in FIG. 6; and FIG. 9 is an end view of a wall means employed in the applicator.

Similar parts of the apparatus are designed in the drawing by the same numerals.

The applicator, as shown in FIG. 1, comprises a rectangular base 1 and a reservoir for adsorbent-containing material 2 on the base, intermediate the ends 3 and 4 thereof. The reservoir has two opposing side walls 5 and 6 mounted vertically adjacent the opposite sides of the base 1, a vertically movable anterior wall or entrance gate 7, and a vertically movable posterior wall or exit gate 8. The walls 7 and 3 are positioned transversely of the base and parallel to the ends 3 and 4 thereof. Grooves 9 and 1% (FIGS. 1 and 7), in which the wall 7 is vertically movable, are provided in the inner sides of the walls 5 and 6 respectively. Grooves 11 and 12, spaced from grooves 9 and respectively, are similarly provided for the wall 8. The walls 7 and 8 enclose a rectangular space which serves as the reservoir.

As shown in FIG. 9, the bottom edge 13 of the anterior wall 7 is fiat. The intersections 14 and 15 of the plane of the edge 13 and the side surfaces of the wall 7, are preferably slightly rounded. The edge 13 (see FIG. 3) normally rests on a surface of a supporting sheet 16 that is in process of being provided with a layer of adsorbent.

The wall 8 has means whereby its lower edge 17 is maintainable in spaced relation to the surface of a sheet to which the adsorbent is applied. The space 18 can be varied by means of adjusting or set screws 19 and 2t) with heads 2-1 and 22 respectively, adjacent either end of the wall 8. The screws 19 and 2% extend through vertical borings (see FIG. 6) in the body of the wall 8. The lower end of a set screw may be pointed as at 23 (FIG. 6), or spherical or rounded as at 24 (FIG. 8). The ends of the set screws normally rest on the surface of a sheet 16. A screw may be threaded with the wall material as at 25 and held in place by a tight fit, or, as in FIG. 8, a screw 26, provided with a head 27, and passing through the height of the Wall 8, may in addition be provided with a lock nut 23. By turning the head of a screw, the end 23 or the end 24 may be made to project a greater or a shorter distance below the lower edge of the wall 8. The space 18 (FIG. 4) can thereby be made wider or narrower. The screws 19 and 20, or screws such as 26 provided with a lock nut 28, are main tainable in fixed position with respect to the lower edge 17 of the wall 8.

A guide plate 29, extending from the reservoir to the end 3 of the base 1 and fastened thereto by screws 30 and 31, has a straight edge 32 in line with the inner side of the side wall 6. The edge 32 serves to guide a supporting sheet into a reservoir between the walls 5 and 6.

Parallel grooves 33, centrally located in the surface of the base 1 and extending longitudinally from the end 3 to the end 4 and beneath the reservoir, prevent undue sticking of a supporting sheet to the base and facilitate movement of a sheet through the reservoir.

In the operation of an applicator, a supporting sheet 16, such as a rectangular sheet of glass, for example, is placed on the base 1. With its side edge against the edge 32 of the guide 29, the sheet is moved toward the entrance gate or anterior wall 7 of the reservoir. The Wall 7 is raised to admit the sheet into the reservoir. The edge 13 is permitted to rest on the surface of the sheet under the weight of the wall 7. The exit gate or posterior wall 3 is raised and the sheet is initially moved only slightly beyond it. A gauge, of the desired thick ness of an adsorbent layer to be applied, is used in setting the wall 8 in its raised position so that the space 18 has the same measurement as the thickness of the adsorbent layer. The screws 13 and 20 are turned to obtain the desired setting. Instead of using a gauge, the setting may be obtained by predetermining the number of turns or part of a turn in a screw needed to project the outer extremities of the tips 23 or 24 the required distance from the edge 17, and to obtain the desired space 18 when the tips rest on the surface of a supporting sheet 16.

A slurry or suspension of an adsorbent, such as, for example, kieselguhr or silica gel, is then poured into the reservoir. The supporting sheet 16 is moved through the reservoir guided by the straight edge 32. A succeeding sheet abutting the end of a preceding sheet may be used to move the latter through the reservoir. Each sheet to be coated is thus successively passed through the reservoir while an adsorbent layer 34 (FIGS. 1 and 2) is formed on the supporting surfaces as they pass beneath the wall 8.

While the supporting sheets are moved through the reservoir, the lower edge 13 of the wall 7 prevents escape of the adsorbent suspension from the reservoir in the wrong direction. The tips of the set screws 19 and 2t glide on the surfaces of the sheets, and while moving the latter, the tips only momentarily deflect the adsorbent material. The suspension readily flows together to fill any space left by the tips.

An adsorbent layer on a sheet, produced as described hereinabove, is subsequently processed in accordance with thin-layer chromatography procedure.

When supporting sheets employed vary in thickness and are to be coated in a given operation, they are arranged in the sequence of diminishing sheet thickness. The

thickness of an adsorbent layer remains the same, and uniformity of its thickness is independent of the thickness of a supporting sheet.

In thin-layer chromatography, glass sheets having a width of 10 centimeters are generally satisfactory as supporting sheets, but the inexpensive, 9 by 12 centimeter photographic plates are also conveniently usable.

To accommodate supporting sheets of diflferent widths in the hereindescribed applicator, adjustment means are provided for changing the distance between the side walls and 6. As shown in FIGS. 3,4 and 7, for instance, screws 35 and 3-6 fasten the wall 5, and screws 37 and 38 fasten the wall 6 to the base 1. The outer sides of the walls 5 and 6 have vertical grooves 39 and 4t and 41 and 42 respectively, similar to the grooves shown on the inner sides of these walls. The screws 35 and 36 are on a line parallel to the sides of the wall 5, and closer to one side than the other. This is true also in the case of screws 37 and 38 with respect to the wall 6. By removing the screws and turning a wall or the walls around from the positions shown in FIG. 7, and replacing the screws, and substituting shorter anterior and posterior walls for walls 7 and =8, the applicator is adjusted to accommodate a narrower supporting sheet, as shown in FIG. 5.

Upon adjustment of the position of the wall 6, as set forth above, the position of the guide '29 is also adjusted. For this purpose, thescrews 3t and 31 that fasten the guide 29 to the base 1 are so placed that when the guide is turned around the edge 43 is in alignment with the inner side of the wall 6 as in FIG. 5 for guidance of the narrower sheet.

When the applicator is set for sheets centimeters in width, it is possible to use two 50 mm. sheets placed side by side for simultaneous coating. Also when set for 9 centimeter sheets, two 45 mm. sheets may be used. For sheets wider than 10 centimeter sheets, the wall 5 alone may be moved further away from wall 6, leaving the latter and the guide 29 in their original positions.

The applicator not only provides adsorbent layers of varied width but also of any length and of uniform thickness. The equipment, as illustrated for the purposes indicated, is considered relatively inexpensive.

What is claimed is:

1. An applicator for use in chromatographic analysis, the said appplicator comprising a reservoir for adsorbentcontaining material, the reservoir having two vertically mounted, opposing side walls; anterior and posterior transverse walls loosely supported in upright position and freely movable upwardly and downwardly; and a base on which the said side walls are mounted and on which sheets on which a layer of said material is to be provided are moved successively beneath the bottom edge of the said anterior wall and of the said posterior wall, the said bottom edge of the said anterior wall resting on the surface of a sheet, and the bottom edge of the posterior wall provided with means for supporting it on the surface of the sheet in spaced relation thereto during the aforesaid movement of a sheet to form thereby a layer of said material on said sheet, and means for adjusting the space between the bottom edge of the posterior wall and the surface of the sheet to provide said layer of said material of predetermined thickness.

2. In anapplicator of the type set forth in claim 1, the said posterior wall of said reservoir having spacing means projecting from the lower edge thereof and adapted to rest on the surface of a sheet to which the said adsorbent-containing material is applied, whereby the thickness of an applied layer of said adsorbent-containing material is uniformly maintained independently of the thickness of said sheet.

3. In an applicator of the type claimed in claim 1, the said means for spacing the bottom edge of said posterior wall from the surface of a said sheet, comprising set screws engaging said posterior wall and having their lower ends projecting downwardly below said edge for contacting, and resting on, said surface of saidflsheet, whereby the space between the said edge and said suriace of said sheet is increased or decreased by turning said screws.

4. In an applicator as claimed in claim 1, means for changing the distance between the sides of said reservoir,

whereby the width of said reservoir is adjustable for coating sheets of different widths.

5. In an applicator comprising a reservoir for a coating material and means for directing a sheet, to be coated, across the bottom of the reservoir through an outlet space beneath the lower edge of a wall of said reservoir to form a layer of said material on said sheet, the said wall having means for supporting it on the surface of said sheet to be coated and for spacing said lower edge of said wall from said surface to provide said outlet space, and said wall being mounted for free movement by means of said support upwardly and downwardly in a layer-forming operation, whereby the thickness of the coating is uniformly maintained independently of the thickness of the said sheet.

6. In an applicator as defined in claim 5 in which the. reservoir is mounted on a base on which a sheet to be coated is moved across the bottom of the reservoir, the said supporting means for said wall comprising set screws having tips that rest on the upper surface of the sheet and that deflect momentarily the coating material during movement of a sheet and permit flow of said coating material to fill any space left by the tips, and the surface of the base adjacent the lower surface of the sheet having a plurality of grooves extending in the direction of movement of'said sheet to facilitate said movement through said reservoir while said supporting means rest on said upper surface of said sheet.

References Cited in the file of this patent UNITED STATES PATENTS 

1. AN APPLICATOR FOR USE IN CHROMATOGRAPHIC ANALYSIS, THE SAID APPLICATOR COMPRISING A RESERVOIR FOR ABSORBENTCONTAINING MATERIAL, THE RESERVOIR HAVING TWO VERTICALLY MOUNTED, OPPOSING SIDE WALLS; ANTERIOR AND POSTERIOR TRANSVERSE WALLS LOOSELY SUPPORTED IN UPRIGHT POSITION AND FREELY MOVABLE UPWARDLY AND DOWNWARDLY; AND A BASE ON WHICH THE SAID SIDE WALLS ARE MOUNTED AND ON WHICH SHEETS ON WHICH A LAYER OF SAID MATERIAL IS TO BE PROVIDED ARE MOVED SUCCESSIVELY BENEATH THE BOTTOM EDGE OF THE SAID ANTERIOR WALL AND OF THE SAID POSTERIOR WALL, THE SAID BOTTOM EDGE OF THE SAID ANTERIOR WALL RESTING ON THE SURFACE OF A SHEET, AND THE BOTTOM EDGE OF THE POSTERIOR WALL PROVIDED WITH MEANS FOR SUPPORTING IT ON THE SURFACE OF THE SHEET IN SPACED RELATION THERETO DURING THE AFORESAID MOVEMENT OF A SHEET TO FORM THEREBY A LAYER OF SAID MATERIAL ON SAID SHEET, AND MEANS FOR ADJUSTING THE SPACE BETWEEN THE BOTTOM EDGE OF THE POSTERIOR WALL AND THE SURFACE OF THE SHEET TO PROVIDE SAID LAYER OF SAID MATERIAL OF PREDETERMINED THICKNESS. 